1. Technical Field
This invention generally relates to pneumatic tires and, more particularly, to a pneumatic tire having an extra layer of rubber that improves tire performance. Specifically, the present invention is directed to a pneumatic tire having an increased rubber gage between the tire body and the belt package to improve the performance of the tire.
2. Background Information
A pneumatic tire used on a typical automobile or truck includes a basic tire carcass member that may have reinforcing cords radially disposed in its body. These reinforcing cords typically radiate out from the center of rotation of the tire. A reinforcing belt package may be positioned on the outer surface of the carcass. The reinforcing belt package may include a layer or layers of reinforcing cords that give the tire strength and durability. Tires also include a tread package having the tire tread that is positioned outside the reinforcing belt package.
In recent times, automobile manufacturers desire tires that are tuned for a specific automobile model. This requirement has developed in part because current suspensions are sensitive enough that tires can make noticeable changes in the ride and handling of an automobile.
Tire manufacturers tune tires by varying the materials that are used in the tire and by varying the configuration of the elements within a tire. Various tire configurations are known for improving characteristics such as road noise, ride, rolling resistance, strength, vibration, and cornering force. Although various tires are known in the art having configurations directed to one or more of these characteristics, a tire is desired that has an improved cornering coefficient, reduced tire vibration levels, reduced coarse road noise with only a small increase in rolling resistance.
In view of the foregoing, the present invention provides a pneumatic tire configuration having increased rubber gage between the body ply and the belt package. The rubber gage is sized to improve the cornering coefficient of the tire while reducing vibrational levels. The increased gage also improves the coarse road noise of the tire. These advantages are achieved without an undesirable increase in rolling loss.
The invention provides a pneumatic tire, including a body having at least one layer of body cord; a belt package having at least one layer of reinforcing cord; a tread package connected to the belt package; and a gage of rubber disposed between the belt package and the body; the gage of rubber spacing the body cord from the reinforcing cord a distance in the range of 0.5 millimeters to 1.5 millimeters.
The invention also provides a pneumatic tire having an extruded sidewall that forms the increased rubber gage between the body ply and the belt package. In one embodiment, the extended sidewall extends all the way across the tire to connect both sidewalls. In another embodiment, each sidewall has an insert that extends partially across the tire to form a pair of opposed belt edge inserts that increase the rubber gage between the body ply and belt packages at the edges of the tire.
The invention provides an improved pneumatic tire having a body, a belt package and a tread package. The improvement including a layer of rubber disposed between the body and the belt package wherein the thickness of the layer of rubber is between 0.5 millimeters and 1.5 millimeters.